This trial is conducted in Europe. The aim of this trial is to determine the relative bioavailability of NNC 90-1170 (liraglutide) when inhaled compared to NNC 90-1170 when injected under the skin.

Inclusion Criteria:

• No clinically important abnormal physical findings
• No clinically relevant abnormalities in the results of laboratory screening evaluation
• Normal (or abnormal but not clinically significant) ECG (electrocardiogram)
• Normal (or abnormal but not clinically significant) blood pressure and heart rate
• Body Mass Index (BMI) between 20-30 kg/m^2 or outwith range but not clinically significant
• Non-smoker
• Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 second (FEV1) at least 85% of predicted normal for age, gender and height
• FVC ratio at least 75% of predicted normal for age, gender and height

Exclusion Criteria:

• A clinically significant illness or infection requiring treatment within the last two months
• Any infection involving the respiratory system or adverse event that may, in the opinion of the principal investigator, interfere with blood glucose homeostasis
• Subjects with first and/or second degree relative(s) with diabetes mellitus
• Donation or loss of greater than 500 ml of blood in the period 0-12 weeks before trial entry
• Alcohol use in excess of 28 units of alcohol per week. A unit of alcohol is equivalent to half a pint of average strength beer, a glass (125 ml) of wine or a pub measure (25 ml) of spirits, sherry or port
• Current addiction to alcohol or substances of abuse
• Females
• Presence of hepatitis B surface antigen, hepatitis C antibody or HIV (human immunodeficiency virus) 1 or 2 antibodies